This project is comprised of four studies on factors determining marital and sexual adjustment, predictors of response to marital-sexual therapy, long-term effects of such therapy, and the psychological and biological factors involved in the syndrome of hypoactive sexual motivation in males. Study I includes a questionnaire study of the life history of dysfunctional patients and a matched control group of normals. Additionally, a number of studies of psychophysiological parameters of sexual functioning are studied in patient and normal populations. Study II involves questionnaire studies of patients pre- and post-therapy, and identification of variables which predict successful and unsuccessful outcome of therapy. Study III is a three-year follow-up of all patients with marital-sexual problems who were seen at this clinic, to determine the long-term effects of therapy, as well as the natural course of adjustment in couples who did not continue in therapy after evaluation. Study IV is an attempt to identify psychological and biological factors in etiology of hypoactive sexual interest in males. Studies of testosterone, LH, estrogen, and prolactin levels are conducted, as well as physiological and psychological evaluation.